The Federalist Party was one of the first political parties in the United States, founded in the late 18th century. It emerged in the 1790s, primarily supporting a strong national government and the ratification of the U.S. Constitution. Key figures included Alexander Hamilton and John Adams, who advocated for policies that promoted commerce and a centralized financial system. The party's influence declined after the War of 1812, as it faced opposition from the Democratic-Republican Party, which favored states' rights and agrarian interests. By the 1820s, the Federalist Party had largely dissolved, marking a significant shift in American political dynamics.